Charging problems, light flicker, voltmeter bounce

[she said she was 18]

Ive had a problem for a long time now that makes my voltmeter needle wiggle or bounce. It has been going on for months and is now getting worse. seems the colder it is under the hood the worse the problem is.

My OBDII adapter is logging between 12.8 to 13.2V now. It accually has recorded dips down to 12.0V. so it seems i am no longer charging. again, the warmer it is the less of a problem i have. 30 mile freeway drive and the needle is solid. 10F degrees and the needle looks like its having a seizure and the lights are flickering. oh yeah, this is a NEW alt (not a rebuild) and the replaced one did the same thing.

is there an issue with the alt cable on these vans? ground is ok, i connected jumper cables to the alt case and a body ground (the one near the relay/fuse center) and it made no difference.

i also have had a problem from time to time with the heater blower coming on high on its own with the heater off, step on the brake and the blower shut off. it doesnt have to do with the switch since as i feathered the pressure on the pedal the speed of the fan would change. I dont see any wiring anywhere near the brake pedal.

I have video of the needle.

[youtube]V32RWOdNdgE&feature=youtu.be&hd=1[/youtube]

please help, it's cold out and i dont want to be walking the kids to school in the morning.

[sfeaver]

You need to get a real volt meter on the battery to see what the voltage really is. Dont go buy what the OBD2 shows, it is always a bit lower. But in your video clip it looks high, I would replace that alternator. Looks like regulator is shot. Check for loose connections though first.

Scott

[she said she was 18]

You need to get a real volt meter on the battery to see what the voltage really is. Dont go buy what the OBD2 shows, it is always a bit lower. But in your video clip it looks high, I would replace that alternator. Looks like regulator is shot. Check for loose connections though first.

Scott

the other alt i have does the same damn thing. infact, this problem is why i replaced it. the only connection that hasn't been checked recently is the solenoid.

havent used a voltmeter recently since the sample rate is to slow to see the flicker. that video was a couple days ago when warm. today it is worse... the needle dropped to straight up and down, 12 o'clock so to speak.its worse now than what u see in the video.

[chevymaher]

I was having interior voltage issues on mine.Gauge was reading lower voltage the more things that were turned on.Off it read 11 volts.Idling nothing on gauge read .5 volt low.Turn on fan it dropped a volt.Turn on lights it dropped another volt.It never dropped below 11.5 volts or so with everything on.I took out the gauge and it tested good.Tested under the hood and I have 12.6 off and 13.8 running anytime.More testing I discovered a high resistance coming from the battery in to the interior.On the power feed through the keyed hot.I jumped voltage from under the hood to the fuse block.now all voltages were the same.I sprayed everything I could plug wise and ignition switch with circuit cleaner.It got better most of the time it close.Every once in a while it dips when everything on.
Things to check are common positive connection for corrosion,located behind the battery.Common ground on radiator core support.Positive battery connection on starter.And the most fun random body grounds all over the vehicle.I found one that was hammered under the drivers seat under the van.Dome lights sure worked better after cleaning that one.As Uncle Bob says happy hunting.

[Thunderball]

I'd take that alternator back and have them test it to be sure you have a good regulator in there. If you know the alternator is GOOD....start looking for bad grounds, batt cables, body grounds, and the stuff in the post above.

I had the same thing, but it was a bad regulator in a new alternator...was blowing fuses and all kinds of stuff from the voltage jumping.

But, go get that new alternator checked....you never know.

[she said she was 18]

Alternator checked out ok. Batt tested bad. Will see what happens when I replace it.

[Corsemoto]

Check the pins on the connector to the alternator, I had an issue with battery voltage fluctuating and the batter light coming on intermittently I thought was the alternator and turned out one of the pins in the connector was not making good contact.